have a mind of its own

mít vlastní vůli

But it quickly became apparent she was wasting her time. The trolley also had a mind of its own and a tendency to advance crablike, sideways.

This too is a real 3D object with moving limbs and a mind of its own.

Of course the horse named Bess, which I was given, had a mind of its own, since it would always be eating and when it was not it only plodded along.

(BNC-B)

» THE HUMAN BODY